1. Field of the Invention
The present invention relates to a fin for a heat exchanger (e.g., an evaporator or a condenser) of an air conditioner.
2. Discussion of Related Art
As shown in FIG. 1, a conventional heat exchanger of an air-conditioner includes a plurality of parallel plates or fins 20 which are arranged between two end plates 10 at predetermined intervals, in order to cool air necessary for an air-cooling operation or in order to heat air for a heating operation when the air circulates. A plurality of heat transmission pipes 30 extend perpendicular to the end plates 10 and the fins 20, and are arranged in zigzag fashion. The pipes conduct refrigerant and transmit heat from the refrigerant to the fins 20. A plurality of return pipes 40 are connected to the ends of adjacent heat transmission pipes 30.
The fin 20 can be flat as shown in FIG. 2A, or wavy (FIG. 2B), or have slit portions in a direction of air current flow as shown in FIG. 2C.
Therefore, a conventional heat exchanger fin has one of the three above-described shapes and is thus of generally uniform shape from an upper end to a lower end thereof. That means that the heat exchanger fin exhibits a uniform heat transfer characteristic across the region between its vertical ends. However, if the velocity distribution of the air current is not uniform from one end to the other, then the rate of heat exchange between the air and fin will not be uniform. For example, if the air velocity S became gradually lower toward the bottom end of the fin, as represented in FIG. 3, for example, then the fin of FIGS. 1 and 2 would not transfer heat at a uniform rate from top to bottom. Another factor that can affect the rate of heat transfer from one end of the fin to the other is the rate of refrigerant flow through the pipes; if the flow is not uniform, then the rate of heat transfer between the pipes and the fins may vary from one end of the fin to the other.
A non-uniform heat exchange rate along the fin can reduce the overall heat exchange efficiency.